The present disclosure relates generally to Moineau-type helical positive displacement pumps and fluid motors and, in an embodiment described herein, more particularly provides for stator/rotor assemblies which have enhanced performance.
Moineau-type fluid pumps and motors rely on an interference fit between an internal helically shaped rotor and an external stator having inwardly extending helically shaped lobes. The interference fit enables the rotor to seal against the stator and form chambers which advance axially along the pump or motor as the rotor rotates relative to the stator. The interference fit is facilitated typically by making the stator lobes out of a resilient material, such as an elastomer or other polymer material.
Unfortunately, over time the repeated flexing of the lobe material, the presence of abrasive particles in the fluid being pumped or driving the motor, chemical breakdown, high temperatures, etc. can lead to failure of the material. It would be desirable to use materials with superior toughness, in order to extend the life of the stator lobes, but since stator linings are generally formed by an injection molding process, the range of materials which can be used is limited to those suitable for injection molding.
Therefore, it will be appreciated that improvements are needed in the art of constructing stator/rotor assemblies for Moineau-type pumps and motors. These improvements may be useful in enhancing the durability of lobes formed in stators and/or on rotors.